scholarly journals A Recent Study of the Relationship between the Precipitation Rate over Saudi Arabia in the Fall and Climatic Indices

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yehia Hafez ◽  
Abdulhaleem Labban
Keyword(s):  
Saudi Arabia ◽  
Southern Oscillation ◽  
Surface Air Temperature ◽  
Inverse Correlation ◽  
Precipitation Rate ◽  
Clear Correlation ◽  
Climatic Index ◽  
Climatic Indices ◽  
Multivariate Enso Index ◽  
The Relationship

This paper presents a recent study of the relationship between precipitation rate (PR) over Saudi Arabia (SA) within the months of the fall season and climatic indices. The fall monthly PR data spanning the study period between 1948 and 2018 is considered. In addition, the monthly climatic index records (arctic oscillation (AO), global surface air temperature (GSAT), multivariate ENSO index (MEI), North Atlantic Oscillation (NAO) index, Nino 3.4 index, and Southern Oscillation Index (SOI)) for the fall months were also considered. The statistical trend, anomaly, and correlation analyses are applied in this study. The results reveal that the sweeping changes in PR show generally positive trends throughout the fall seasons of the past decades. Moreover, the climatic indices have an effect on the PR over SA within the fall months and season. During the study period, the most substantial relationship recorded, with an inverse correlation of −0.7, is between the PR over SA and the climatic index of GSAT for September and October. Moreover, there is a clear correlation of +0.5 between the PR over SA and the ENSO and Nino 3.4 index for October and November.

scholarly journals PLANETARY-SCALE CLIMATIC INDICES AND RELATIONSHIP BETWEEN DECADAL VARIABILITY OF RAINFALL IN NORTHEASTERN AND SOUTHERN BRAZIL

2013 ◽  
Vol 31 (1) ◽  
pp. 31 ◽  
Author(s):  
Luciana Figueiredo Prado ◽  
Ilana Wainer
Keyword(s):  
Decadal Variability ◽  
Southern Oscillation ◽  
Global Precipitation Climatology Project ◽  
Tropical Atlantic ◽  
Climatic Index ◽  
Climatic Indices ◽  
Atmospheric Research ◽  
Precipitation Climatology ◽  
Environmental Prediction ◽  
Global Precipitation

This work analyzes the relationship between climatic index and rainfall in the Northeastern (NE) and Southern (S) Brazil, in decadal timescale. The climatic indices were obtained from the reanalysis data from NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research) between 1948 and 2008. Subsequently, (indices and rainfall correlation coefficients derived from the GPCP (Global Precipitation Climatology Project) dataset were calculated using filtered and non-filtered time series, within the decadal frequency). The results show that ElNi ˜no Southern Oscillation (ENSO) is the main phenomenon influencing NE rainfall due to related changes in tropical circulation while the Intertropical Convergence Zone (ITCZ) annual cycle also affects rainfall in the NE to a lesser extent. Meanwhile, in the Southern region, the most important phenomenon is the Southern Annular Mode (SAM) which controls cyclones activity in mid-latitudes. The Tropical Atlantic dipole index (ADI) also influences the rainfall in the Southern, and this might be related to moisture being transported from the ocean to the continent, which is then carried to the South by the Low Level Jet. It is also suggested that the decadal variability of the Tropical Atlantic Ocean and its influence on the precipitation in NE andS regions of Brazil are episodic because no significant correlations were obtained at decadal frequency. Finally, the spectral analysis revealed that the interannual timescale is the main frequency of variability in both studied regions, affecting differently each one of them. RESUMO: Este trabalho analisa as relações entre índices climáticos e a precipitação no Nordeste (NE) e Sul (S) do Brasil, em escala decadal. Os índices climáticos foram obtidos a partir de dados da reanálise do NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research), para o período de 1948 a 2008. Posteriormente, foram obtidos os coeficientes de correlação entre os índices e as anomalias de precipitação advindas do banco de dados do GPCP (Global Precipitation Climatology Project) nestas regiões, utilizando séries não filtradas e séries filtradas na frequência decadal. Os resultados sugerem que o principal fenômeno que modula a precipitação no NE é o El Ni˜no-Oscilação Sul (ENOS), devido às alterações na circulação tropical, e também o ciclo anual da Zona de Convergência Intertropical (ZCIT), que modula a estação chuvosa do NE. Na região S, o fenômeno que mais influencia a precipitação em escala decadal é o Modo Anular Sul (SAM),por modular a atividade ciclogenética em latitudes médias, além do índice do dipolo do Atlântico Tropical (DA), que pode estar ligado ao aporte de umidade oceânica para o continente, e levada ao S pelo jato de baixos níveis. Também se sugere que a variabilidade decadal do Atlântico tropical e sua influência na precipitação no NE sejam episódicas, e não periódica, já que não foram obtidas correlações importantes para este índice, na frequência estudada. Finalmente, a análise espectral revelouque a escala interanual é a principal frequência de variabilidade temporal em ambas as regiões, com efeitos diversos em cada uma delas.Palavras-chave: precipitação, ENOS, Atlântico, SAM. 

The history of using rainfall data to improve production in the grain industry in Australia—from Goyder to ENSO

2016 ◽  
Vol 67 (5) ◽  
pp. 467 ◽  
Author(s):  
Derek Yates ◽  
R. Willem Vervoort ◽  
Budiman Minasny ◽  
Alex McBratney
Keyword(s):  
Southern Oscillation ◽  
Historical Review ◽  
Quality Data ◽  
Annual Rainfall ◽  
Climatic Data ◽  
Climatic Index ◽  
Millennium Drought ◽  
History Of ◽  
Complex Relationships ◽  
The Relationship

Rainfall is a major driver for dryland wheat yields across Australia. Many authors have covered issues such as rainfall trends in Australia, and much of this information has been reviewed and updated in recent years in relation to the Millennium drought and associated concerns about climate change. However, despite a long history of work relating rainfall to grain yields, there has been no overall historical review of attempts at predictive methods and their reliability. Although many of these attempts have now been abandoned or revised, and science has moved in different directions, a review is useful to identify historical patterns and to recognise recurring themes. This might lead to new science questions and a re-appreciation of older findings. The aim of this study is therefore to review the overall literature on this topic, provide a historical timeline, and summarise the achievements and any remaining research questions. The early use of climatic data in Australia was to categorise existing and likely areas for production, with production, not surprisingly, being the emphasis. The search for a crop or climatic index was possibly initiated in an attempt to understand or simplify the complex relationships between crops and the environment. No single index has proved universally applicable, but some acceptance of early growing-season rains as an indicator seems common. The development of complex climatic models, and the availability of quality data for agricultural systems models, has allowed further quantification of the relationship between crops and climate, especially on a seasonal basis. There is little doubt that the relationship between the climatic southern oscillation phenomenon and seasonal rainfall patterns in Australia is important, but its absolute definition remains elusive. From a producer’s perspective, relationships between rainfall at specific (indicator) periods and seasonal or annual rainfall, as appropriate to specific crops, would be useful simple indicators because many farmers already maintain their own rainfall records.

scholarly journals The Relationship between the Wintertime Cold Extremes over East Asia with Large-Scale Atmospheric and Oceanic Teleconnections

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 813 ◽  
Author(s):  
Ye Yang ◽  
Naru Xie ◽  
Meng Gao
Keyword(s):  
East Asia ◽  
Large Scale ◽  
Southern Oscillation ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Boreal Winter ◽  
Key Factors ◽  
Teleconnection Patterns ◽  
The Relationship ◽  
Cold Extremes

The influence of large-scale teleconnection patterns, Western Pacific (WP), Arctic Oscillation (AO) and El Niño-Southern Oscillation (ENSO), on the minimum surface air temperature (Tmin) anomalies and extremes over East Asia during the boreal winter from 1979 to 2017 were investigated by the composite analysis in terms of atmospheric and oceanic processes. The relationship between the Tmin and the geopotential height at 500 hPa (Z500) as well as sea surface temperature (SST) were first examined. Then we explored and estimated the contribution of the teleconnection patterns to the occurrence of extremely cold days and months quantitatively, and discussed other key factors in relation to the cold extremes. The WP and AO patterns play an important part in the prevalence of significant Tmin variability, whereas the effect of ENSO is relatively weak. Most of the cold extremes tend to appear in the negative phase of teleconnections, while there some extremes that occur in the opposite phase. In addition, the extreme months are more related to the preferred phase of the dominant pattern when compared to days. We conclude that the daily extremes are primarily triggered by the local-synoptic atmospheric circulations embedded in the large-scale teleconnection patterns, while the monthly extremes have a closer relationship with these low-frequency patterns.

scholarly journals Summer monsoon rainfall over Bangladesh in relation to Multivariate ENSO Index

MAUSAM ◽  
2021 ◽  
Vol 51 (3) ◽  
pp. 255-260
Author(s):  
O. P. SINGH ◽  
TARIQ MASOOD ALI KHAN ◽  
SAZEDUR RAHMAN ◽  
SALAH UDDIN
Keyword(s):  
Monsoon Rainfall ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Surface Wind ◽  
Surface Air Temperature ◽  
Principal Component ◽  
Complete Information ◽  
Summer Monsoon Rainfall ◽  
Multivariate Enso Index ◽  
Enso Index

The relationship between monthly rainfall over Bangladesh during monsoon season and bi-monthly Multivariate ENSO Index (MEI) pertaining to the period from first week of previous month to first week of the month under consideration, has been investigated. The MEI is calculated as the first Principal Component (PC) of six variables over the tropical Pacific, viz., sea surface temperature, sea level pressure, zonal and meridional components of the surface wind, surface air temperature and total cloudiness fraction of the sky. The MEI values for prognostic purposes are available by the first week of every month. MEI is better for monitoring ENSO than other indices like Southern Oscillation Index (SOI) or various SST indices as it integrates complete information on ENSO and reflects the nature of complete ocean atmosphere system. Positive values of MEI indicate warm ENSO phase (EI-Nino) and negative ones represent cold phase (La-Nina).   The results of the present study show that June rainfall of Bangladesh is adversely affected by the ENSO. But interestingly Bangladesh seems to receive more than normal rainfall during August of ENSO years. ENSO does not seem to have any significant adverse impact on July and September rainfall of Bangladesh. The results of the study may find applications in foreshadowing monsoon rainfall over Bangladesh on a monthly scale.

Interdecadal Changes in the Relationship between Wintertime Surface Air Temperature over the Indo-China Peninsula and ENSO

2021 ◽  
pp. 1-45
Author(s):  
Juncong Li ◽  
Zhiping Wen ◽  
Xiuzhen Li ◽  
Yuanyuan Guo
Keyword(s):  
Air Temperature ◽  
Southern Oscillation ◽  
Surface Air Temperature ◽  
Seasonal Prediction ◽  
Atmospheric Model ◽  
Sea Surface ◽  
Warm Temperature ◽  
Southwesterly Wind ◽  
The Relationship ◽  
Sst Anomalies

AbstractInterdecadal variations of the relationship between El Niño-Southern Oscillation (ENSO) and the Indo-China Peninsula (ICP) surface air temperature (SAT) in winter are investigated in the study. Generally, there exists a positive correlation between them during 1958–2015 because the ENSO-induced anomalous western North Pacific anticyclone (WNPAC) is conducive to pronounced temperature advection anomalies over the ICP. However, such correlation is unstable in time, having experienced a high-to-low transition around the mid-1970s and a recovery since the early-1990s. This oscillating relationship is owing to the anomalous WNPAC intensity in different decades. During the epoch of high correlation, the anomalous WNPAC and associated southwesterly winds over the ICP are stronger, which brings amounts of warm temperature advections and markedly heats the ICP. Differently, a weaker WNPAC anomaly and insignificant ICP SAT anomalies are the circumstances for the epoch of low correlation. It is also found that substantial southwesterly wind anomalies over the ICP related to the anomalous WNPAC occur only when large sea surface temperature (SST) anomalies over the northwest Indian Ocean (NWIO) coincide with ENSO (namely when the ENSO-NWIO SST connection is strong). The NWIO SST anomalies are capable of driving favorable atmospheric circulation that effectively alters ICP SAT and efficiently modulates the ENSO-ICP SAT correlation, which is further supported by numerical simulations utilizing the Community Atmospheric Model, version 4 (CAM4). This paper emphasizes the non-stationarity of the ENSO-ICP SAT relationship and also uncovers the underlying modulation factors, which has important implications for the seasonal prediction of the ICP temperature.

Rendimento de grãos de soja e de milho, no Rio Grande do Sul, não difere entre eventos El Niño Oscilação Sul

Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina ◽  
Significant Difference ◽  
Income Data ◽  
The Relationship

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.

scholarly journals The relationship between CD204 M2-polarized tumour-associated macrophages (TAMs), tumour-infiltrating lymphocytes (TILs), and microglial activation in glioblastoma microenvironment: a novel immune checkpoint receptor target

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maher Kurdi ◽  
Badrah Alghamdi ◽  
Nadeem Shafique Butt ◽  
Saleh Baeesa
Keyword(s):  
Microglial Activation ◽  
Inverse Correlation ◽  
Idh1 Mutation ◽  
High Expression ◽  
Kaplan Meier ◽  
Significant Difference ◽  
Tumour Infiltrating Lymphocytes ◽  
Infiltrating Lymphocytes ◽  
The Relationship ◽  
Low Expression

Abstract Background Tumour associated macrophages (TAMs) and tumour infiltrating lymphocytes (TILs) are considered dominant cells in glioblastoma microenvironment. Aim The purpose of this study was to assess the expression of CD204+ M2-polarized TAMs in glioblastomas and their relationship with CD4+TILs, Iba+microglia, and IDH1 mutation. We also exploreed the prognostic value of these markers on the recurrence-free interval (RFI). Methods The expressions of CD204+TAMs, CD4+TILs, and Iba1+microglia were quantitively assessed in 45 glioblastomas using immunohistochemistry. Kaplan–Meier analysis and Cox hazards were used to examine the relationship between these factors. Results CD204+TAMs were highly expressed in 32 tumours (71%) and the remaining 13 tumours (29%) had reduced expression. CD4+TILs were highly expressed in 10 cases (22%) and 35 cases (77.8%) had low expression. There was an inverse correlation between CD204+TAMs and CD4+TILs, in which 85% of tumours had a high expression of CD204+TAMs and a low expression of CD4+TILs. Nevertheless, there was no significant difference in IDH1 mutation status between the two groups (p = 0.779). There was a significant difference in Iba1+microglial activation between IDH1mutant and IDH1wildtype groups (p = 0.031). For cases with a high expression of CD204+TAMs and a low expression of CD4+TILs, there was a significant difference in RFI after treatment with chemoradiotherapy or radiotherapy (p = 0.030). Conclusion Glioblastoma with a dense CD204+TAMs and few CD4+TILs is associated with IDH1wildtype. These findings suggest that TAMs masks tumour cell and suppress T-cell tumoricidal functions via immunomodulatory mechanisms. Blockade of the CD204-TAM receptor may prevent this mechanism and allow the evolution of TILs.

Diagnosing Sources of U.S. Seasonal Forecast Skill

2006 ◽  
Vol 19 (13) ◽  
pp. 3279-3293 ◽  
Author(s):  
X. Quan ◽  
M. Hoerling ◽  
J. Whitaker ◽  
G. Bates ◽  
T. Xu
Keyword(s):  
Air Temperature ◽  
Southern Oscillation ◽  
Surface Air Temperature ◽  
Seasonal Forecast ◽  
Forecast Skill ◽  
Diagnostic Methods ◽  
Sea Surface ◽  
Empirical Methods ◽  
Spatial Coverage ◽  
Sst Anomalies

Abstract In this study the authors diagnose the sources for the contiguous U.S. seasonal forecast skill that are related to sea surface temperature (SST) variations using a combination of dynamical and empirical methods. The dynamical methods include ensemble simulations with four atmospheric general circulation models (AGCMs) forced by observed monthly global SSTs from 1950 to 1999, and ensemble AGCM experiments forced by idealized SST anomalies. The empirical methods involve a suite of reductions of the AGCM simulations. These include uni- and multivariate regression models that encapsulate the simultaneous and one-season lag linear connections between seasonal mean tropical SST anomalies and U.S. precipitation and surface air temperature. Nearly all of the AGCM skill in U.S. precipitation and surface air temperature, arising from global SST influences, can be explained by a single degree of freedom in the tropical SST field—that associated with the linear atmospheric signal of El Niño–Southern Oscillation (ENSO). The results support previous findings regarding the preeminence of ENSO as a U.S. skill source. The diagnostic methods used here exposed another skill source that appeared to be of non-ENSO origins. In late autumn, when the AGCM simulation skill of U.S. temperatures peaked in absolute value and in spatial coverage, the majority of that originated from SST variability in the subtropical west Pacific Ocean and the South China Sea. Hindcast experiments were performed for 1950–99 that revealed most of the simulation skill of the U.S. seasonal climate to be recoverable at one-season lag. The skill attributable to the AGCMs was shown to achieve parity with that attributable to empirical models derived purely from observational data. The diagnostics promote the interpretation that only limited advances in U.S. seasonal prediction skill should be expected from methods seeking to capitalize on sea surface predictors alone, and that advances that may occur in future decades could be readily masked by inherent multidecadal fluctuations in skill of coupled ocean–atmosphere systems.

scholarly journals Relation between photochromic properties and molecular structures in salicylideneaniline crystals

2012 ◽  
Vol 68 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Kohei Johmoto ◽  
Takashi Ishida ◽  
Akiko Sekine ◽  
Hidehiro Uekusa ◽  
Yuji Ohashi
Keyword(s):  
Dihedral Angle ◽  
Steric Hindrance ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Clear Correlation ◽  
X Ray Diffraction ◽  
Photochromic Properties ◽  
X Ray ◽  
Benzene Rings ◽  
The Relationship

The crystal structures of the salicylideneaniline derivatives N-salicylidene-4-tert-butyl-aniline (1), N-3,5-di-tert-butyl-salicylidene-3-methoxyaniline (2), N-3,5-di-tert-butyl-salicylidene-3-bromoaniline (3), N-3,5-di-tert-butyl-salicylidene-3-chloroaniline (4), N-3,5-di-tert-butyl-salicylidene-4-bromoaniline (5), N-3,5-di-tert-butyl-salicylidene-aniline (6), N-3,5-di-tert-butyl-salicylidene-4-carboxyaniline (7) and N-salicylidene-2-chloroaniline (8) were analyzed by X-ray diffraction analysis at ambient temperature to investigate the relationship between their photochromic properties and molecular structures. A clear correlation between photochromism and the dihedral angle of the two benzene rings in the salicylideneaniline derivatives was observed. Crystals with dihedral angles less than 20° were non-photochromic, whereas those with dihedral angles greater than 30° were photochromic. Crystals with dihedral angles between 20 and 30° could be either photochromic or non-photochromic. Inhibition of the pedal motion by intra- or intermolecular steric hindrance, however, can result in non-photochromic behaviour even if the dihedral angle is larger than 30°.

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